The present invention relates to a massage machine suitable for rocking a chair main body in a forward-backward direction.
Conventionally, a massage machine has been known, in which a movable frame and a fixed frame are coupled to each other, a seat portion and a backrest portion are attached to the moveable frame, and a pivot point is set at a fulcrum Such a massage machine is capable of rocking the movable frame in the forward-backward direction about the pivot point with respect to the fixed frame by driving a rocking drive unit with a motor (see FIGS. 4 and 5 in Japanese Unexamined Patent Application Publication No. 2011-72595, for example).
In addition, another massage machine has also been known, in which a supported portion and a base portion are coupled to each other with two front and back links, a seat portion and a backrest portion are attached to the supported portion, and which is capable of rocking the supported portion in the forward-backward direction with respect to the base portion (see FIG. 14 in Japanese Unexamined Patent Application Publication No. 11-137626, for example).
According to the massage machine disclosed in JP 2011-72595, however, a movable frame 11 (chair main body) is supported by a fixed frame 10 (base) while only a pivot point A2 is set to a movable portion, and therefore, the load of a user is concentrated and acts on the movable portion. Therefore, excessive load acts on the rocking mechanism portion, and there is a problem in that smooth rocking motion of the movable frame is prevented when the movable frame is rocked.
On the other hand, in the massage machine disclosed in Japanese Patent Application Publication No. 11-13762, since both front and back ends of a supported portion 56 (chair main body) are coupled to a base portion 5 (base) with two links 54 and 54, the load of a user acts on the movable portion (coupling portions 55 and 55 between the supported portion and the base portion) of the supported portion 56 with respect to the base 5 and is distributed in the forward-backward direction. Therefore, less load acts on the rocking mechanism portion during the rocking of the supported portion 56, and it is possible to smoothly rock the supported portion 56.
However, since the massage machine disclosed in Japanese Patent Application Publication No. 11-137626, is configured such that a lower end of the link 54 is coupled to the supported portion 56 (chair main body) and an upper end of the link 54 is coupled to the base portion 5 (base), it is necessary to locate the coupling portion to the link 54 in the base portion 5 at a higher position than a floor surface, and there is a problem in that the height of entire massage machine becomes larger.
Thus, the present invention has been made in order to solve the aforementioned problems, and an object thereof is to provide a massage machine, which is capable of stably rocking a chair main body in the forward-backward direction, the overall height of which is suppressed.